Four-Stroke Engine Brake Lever Mechanism for Dual-Phase Braking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine brake devices for four-stroke internal combustion engines require significant constructional effort, occupy large space, and have numerous parts, making them susceptible to malfunctions and difficult to produce, while they are not capable of achieving dual-phase braking effectively.
Innovation Solution
The exhaust lever is divided into two parts, rotatably mounted about a common axis, with a locking element allowing rotational connection between them, enabling dual-phase braking by shifting the brake cam relative to the exhaust cams by approximately 90°, reducing mechanical loading and wear, and allowing the brake lever to act directly on one exhaust valve while the exhaust lever acts indirectly on both.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate engine-brake valve is assigned in addition to exhaust valves, then engine braking function is achieved, but device complexity and space requirements increase
Solution Approach 1:
The exhaust valve serves dual purposes: normal exhaust function during driving operation and engine braking function when the locking element connects the brake lever parts. This eliminates the need for a separate engine-brake valve, reducing device complexity while maintaining both functions
Solution Approach 2:
The brake lever parts are integrated with the exhaust lever structure, sharing a common lever axis and rotational connection. This merging of brake and exhaust valve actuation mechanisms reduces the number of separate components and simplifies the overall valve system
2Ease of operation
If hydraulic or pneumatic actuation is used for engine-brake valves, then braking control is achieved, but constructional effort and space requirements increase
Solution Approach 1:
The cam mechanisms automatically actuate the brake lever parts through mechanical action during engine braking operation, without requiring external hydraulic or pneumatic systems. The system uses the engine's own motion to trigger the braking function
Solution Approach 2:
The patent replaces complex hydraulic or pneumatic actuation systems with a simpler mechanical cam-based actuation system. The cam profiles directly translate engine motion into valve actuation, eliminating the need for high-pressure oil systems and electrohydraulic valves
3Productivity
If the exhaust control is advanced by approximately one working stroke, then dual-phase braking effect is achieved, but mechanical loading and wear increase
Solution Approach 1:
The exhaust lever is divided into two separate parts (first exhaust lever part and second exhaust lever part) that can rotate independently about the lever axis. This segmentation allows each part to handle specific phases of operation, distributing mechanical loads and reducing wear on individual components while enabling dual-phase braking
4Adaptability or versatility
If multiple individual parts are used in engine-brake devices, then braking function is achieved, but susceptibility to malfunctions increases
Solution Approach 1:
The brake lever parts are rotationally connected to the exhaust lever parts through a locking element, creating an integrated mechanism. This reduces the number of separate individual parts that could fail independently, while maintaining the ability to perform both normal exhaust operation and engine braking function
Data Source
AI summary
A four-stroke internal combustion engine having an engine brake, at least one exhaust valve per cylinder, each valve actuated by a camshaft and at least one first valve lever arrangement, and a device which advances the exhaust control, with the valve lever arrangement having an exhaust lever actuated by an exhaust cam and a brake lever actuated by a brake cam. The brake lever has a first brake lever part on the side of the camshaft and a second brake lever part on the side of the exhaust valve, with the two brake lever parts being rotatably mounted independent of each other about a lever axis and being rotationally connectable with each other in engine braking operation by a locking element which is adjustable between two positions.